Cut away the old caulk from around the vent pipe.
How to replace a roof vent pipe.
Carefully pry up the shingles around the roof jack using a flat pry bar.
Slide the new flashing over the vent pipe and under the shingles above the pipe.
Slip a flat bar under the edge of the vent flashing and pop the nails up photo 1.
Use the knife blade to scrape the pipe clean and smooth.
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Use a pocketknife to scrape rough edges and sharp points from upper end of plastic vent pipe.
The penetration will be oval to have a round pipe exit vertically through a pitched roof you need an oval hole in the roof.
How to replace the box vent on your roof.
Works for any size pipe.
With the pipe in a vertical position trace around the pipe using a pencil.
Go into your attic.
Video turorial on how to change out a plumbing vent boot.
Pry up the old jack and remove it by pulling it up over the vent pipe.
Remove any roofing nails and slide out the shingles.
Position the vent pipe up to the bottom of the roof.
Pull the old flashing up over the vent pipe and scrape any old caulk and debris off the roof.